In manufacturing settings, it is often necessary to hold and transport components. For example, in the field of electronics circuit assembly, electronic components are often carried from a supply of components to a specific location on a circuit board for attachment thereto. The components may be of several different types, including surface mount components. Particular examples include memory chips, integrated circuit chips, resistors, connectors, processors, capacitors, gate arrays, etc. It is possible to transport small and delicate components using a carrier tape/cover tape system, such as that disclosed in U.S. Pat. No. 5,325,654.
The electronic industry is continually moving towards smaller devices and thus smaller components, which in turn require more delicate and precise removal of such components from the carrier tape/cover tape system. Most known cover tapes use heat activated adhesive (HAA) or pressure sensitive adhesive (PSA) to bond the cover tape to the carrier tape. Removal of the components is done by first carefully peeling or debonding the cover tape off of the carrier tape to expose the component to vacuum nozzles or other component handling equipment for safe component removal.
However, known cover tapes present several operational difficulties. For instance, peeling the cover tape from the carrier tape can create “shocky”, rough, nonuniform and inconsistent peels, which cause movement of the carrier tape/cover tape that can displace the small components. Shocky peels have also been known to eject the small components out of the pocket in the carrier tape, thus causing miss-picks and eventual shut down of automated component handling equipment.
The peel force of adhesive cover tape can vary considerably depending on the width of the cover tape and the type of carrier tape used. Wider HAA cover tapes require higher heat to get secure bonds. Likewise, wider PSA cover tapes have lower peel forces and require wider adhesive exposure to get secure bonds. In addition, cover tapes that are designed for one type of carrier tape (e.g., polystyrene) do not always have good performance on other types of carrier material (e.g., polycarbonate). Even if cover tapes do nominally work with different types of carrier tapes, they may have less than optimum peel force and nonuniform peels. Moreover, HAA cover tapes also have poor stability as the peel force degrades with time and temperature.